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DESIGN & PRODUCTS AUTOMOTIVE ELECTRONICS Fig. 4: Mixel’s Rx+ D-PHY hard macro. In Mixel’s implementation, the receive side is targeted and the lanes are optimized to align with the major transfer direction from the camera to the S32V. The block diagram of the Mixel D-PHY Rx+ is shown in figure 4. A key feature in the Rx+ is the area optimized Tx side. Adding a minimally invasive Tx adds loopback support and eases the set up required in a post silicon production test. Not only do you get performance and power, but silicon testability as a result of this special implementation. Mixel’s D-PHY Rx+ follows the MIPI D-PHY specification but adds this important custom option. Note that the MIPI Alliance defines its specifications to allow optimizations during implementation. In this way, customers and vendors can work within the pin limit constraints and data rate transfer requirements of the system, optimizing for power and efficiency, and in this case, also testability. Safety and reliability Certainly, operational reliability and robustness are fundamental to the parts used in automobiles. Because ADAS features are mission critical for making us safer as we drive, safety standards are essential. But even non-critical systems must operate reliably across a wide, and often severe, range of environmental conditions. Suppliers to the auto industry, and the suppliers to those suppliers, must meet standards like AEC-Q100, which establishes common electrical component qualification requirements for ICs, IEC 61508, intended to be a basic functional safety standard applicable to all kinds of industries, and ISO 26262, which establishes standards for functional safety of electrical and/or electronic systems in production automobiles. In this case, Mixel, as a supplier of IP to NXP, designs its MIPI IP with reliability and robust operation from the start, and then does the extra work to make sure the IP meets these standards. For example, Mixel’s D-PHY meets the AEC-Q100 Grade 0 specification. Validating the design requires extensive use of statistical simulations incorporating aging effects and temperature variation. Mixel varies the critical parameters in a normal distribution running simulations so each device variance is accounted for. The design target is to perform within a six sigma range. Such simulations require careful planning such that the performance becomes predictable within the expected tolerances of the D-PHY’s operating environment. The performance is further validated with extensive testing and characterization done, both by Mixel, and by NXP. The extra effort results in reliable and safe system operation. Using MIPI in radar, lidar and beyond As suppliers move to extend ADAS in the direction of autonomous driving, MIPI specifications will continue to evolve and deploy where they fit. Radar (millimeter wave radio) and Lidar (light) sensor subsystems also require the transfer of large amounts of data. These systems can use MIPI interfaces to transmit data from the Analog Front End connected to ADC/ Baseband and signal processing components or directly to the system-level fusion processing systems where appropriate action can be initiated. In applications like adaptive cruise control, the MIPI CSI-2 interface fits perfectly to connect the RF front end to the radar processor (for example, the NXP S32R27, which uses Mixel MIPI D-PHY to connect to NXP RF front end devices like the MR3003). Here, continuous burst transmissions need to be analyzed, to detect objects and judge vehicle-to-vehicle relative speeds, and ultimately to adjust the throttle. These are high bandwidth data transfers with multiple arrays of analog to digital converters (ADCs) to support data collected from long and short-range transmissions. Whether the sensors use sight or light, MIPI interfaces continue to be deployed inside the automobile sensor modules supporting these critical data transfers. MIPI member companies like NXP and Mixel continue to deploy MIPI specification interfaces, both in system-level designs and as IP. Other MIPI member companies are deploying these interfaces where they fit in automobiles, and other systems as well. This is taking place anywhere that can benefit from interfaces defined for efficiency and performance. The flexibility that the MIPI Alliance has built into their specification definitions allows vendors and customers to develop interfaces optimized to each application. This “perfect fit” of application requirement to interface architecture is serving the emerging auto industry in much the same way that it has served and continues to serve the mobile smartphone market. The auto industry continues to enhance the systems that will make a car operate more like a mobile device. We are moving closer to enjoying fast, safe, informative and entertaining driving, stress free. Our cars have more systems that need MIPI Alliance’s performance and power optimized interfaces. The MIPI Alliance and its member companies continue to deploy the systems interfaces that will transform your car into an autonomous mobile device for the benefit of us all. Fig. 5: Radar transceiver to radar processor. 36 Electronic Engineering Times Europe March 2017 www.electronics-eetimes.com


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